Wettability of colloid-imprinted carbons by contact angle kinetics and water vapor sorption measurements

As an example of nanoporous carbon materials, colloid-imprinted carbons (CICs) have been reported to have promising properties for use in a variety of applications. However, the wettability of these carbons has not been investigated as yet. In this work, CICs with different pore sizes (20–50 nm) were synthesized and heat treated at 1500 °C under a N2 atmosphere. Heat treatment was found to not alter the nanoporous structure of these carbons, but did significantly decrease their oxygen content. Contact angle kinetics (CAK) and water vapor sorption (WVS) experiments were carried out to determine the wettability of the CICs, before and after heat treatment, showing that the as-synthesized CICs surfaces are much more hydrophilic when compared to commercial carbon black (Vulcan carbon, VC). The high hydrophilicity of the CICs is likely due to their high surface-specific oxygen atomic density (∼10 μmol m−2). Further heat treatment significantly decreases the hydrophilicity of CICs because of the removal of oxygen atoms from their surfaces, as also reflected by their cyclic voltammetric response in acidic solutions.